This invention relates in general to attachment brackets for vehicles, and more particularly for lockable attachment brackets for holding ladders on vehicles.
Ladders are commonly used on service vehicles catering to industrial, commercial and residential clients . . . they can be found most everywhere. Many trucks and other vehicles used to transport equipment have racks on which a ladder may be placed. Typically, one finds racks for holding ladders on pick-up trucks and on the roofs of small vans. These racks are frequently clamped to roof drip rails, however, they do not include means for securing the ladder to the rack.
Consequently, ladders are frequently tied to the vehicle rack and may become loose during transport. Ropes used for tying oftentimes loosen and become undone due to vibration, so-called xe2x80x9cbungeexe2x80x9d cords and rubber straps break; such events can injure the user and create severe safety problems for others if the vehicle is moving. Furthermore, when left unattended, ladder theft is a common problem with these tying methods. Many locking systems use C- or U-shaped brackets which allow a rolling-out from the locked position making theft relatively simple.
Methods of attachment other than tying are also not without their problems. Conventional chain/padlock combinations rust and are somewhat cumbersome to use. In inclement weather, ease and rapidity of untying or unlocking is of special importance; conventional ladder locks usually take several minutes to engage and disengage. Additionally, typical means for locking a ladder to a rack have protrusions. These cause snagging on trees and wires, etc., which is commonplace since the vast majority of these service vehicles go to residences.
Therefore, an improved lockable attachment bracket for holding a ladder on a vehicle rack, and preventing its unauthorized removal, would be highly advantageous. The lock/bracket combination should be easy to use, quick to lock and unlock, and simple enough in design and rugged enough in construction to provide years of dependable service.
Applicant is aware of prior art ladder supports. For example, U.S. Pat. No. 5,154,258 issued to Krukow is for a lockable ladder securing bracket which includes a spring-loaded pivoting arm which clamps down over a ladder rung to hold the ladder in place. The pivoting arm is L-shaped and is attached to a lever which can be locked in place (with a conventional separate lock). A second arm prevents the ladder from swinging out under the L-shaped arm. This invention is a relatively complicated system requiring: 1) a pair of spaced brackets; 2) the need to engage both the ladder frame and the ladder rung; and 3) a significant number of elements including a separate lock and appropriate tools.
Nikula et al discloses in U.S. Pat. No. 5,383,533 a ladder clamping tool for holding a ladder in a fixed position relative to a rain gutter which conceivably could be used to hold a ladder on a rack as well. However, being of a general C-shaped configuration, it suffers from the possibility of loosening and twisting due to vibration and slippage through the opening of the C; similar problems exist with a U-shaped configuration. Additionally, the lock C-clamp of U.S. Pat. No. 4,912,949 issued to Bowers might also be used to act as a ladder lock on a service vehicle rack, yet still suffers from some of the C-clamp problems.
In view of the above-identified problems associated with the prior art methods of securing a step ladder or an extension ladder to a cargo-style service vehicle rack, the objects of the instant invention are enumerated below.
It is an object of this invention to provide a ladder lock of few components and of essentially one-piece construction, thereby eliminating the use of straps and ties.
It is an additional object to provide a ladder lock wherein the lock is fully integrated with the bracket.
It is a further object to provide a ladder lock without protrusions, said protrusions oftentimes snagging tree branches, wires, etc., especially when working in residential areas.
It is an additional object to provide a ladder lock which can be engaged and disengaged in less than one minute.
It is another object to provide a ladder lock of totally enclosed structure to avoid the potential problems associated with C- and U-shaped brackets.
It is a further object to provide a ladder lock which is prevented from lengthwise sliding with both width adjusting holes and tension adjusting screws for height control.
It is an additional object to provide a ladder lock bracket which can be accommodated to fit on the commonly seen pipe racks.
It is also an object to provide a ladder lock bracket which can be accommodated to fit on a vehicle having only cross support racks as well as those having side rails.
It is yet a further object to provide a ladder lock whose design allows simplicity of manufacture, minimization of cost and rapidity of set-up and removal.
It is thus an object of the invention to eliminate the need for additional tools, for more than one bracket in each application, and for a separate padlock, for example.
A ladder lock for connecting a ladder to a vehicular ladder rack for safety and security comprising: three portions of narrow flat metal stock fastened together to form a frame structure in a rectangular configuration; a first portion connected to a second portion by a back flap hinge; said second portion connected to a third portion; a strike plate integrally affixed to the free end of said first portion; a tension latch assembly, having a lock as an integral part thereof, affixed to the free end of said third portion for latching with said strike plate thereby closing and locking the frame about said ladder and said ladder rack.
The ladder lock wherein said hinge having a plurality of holes therein for alignment with holes in said first or second portions for receiving fasteners for adjusting the width of the frame structure. The ladder lock further comprising a threaded stud for insertion into said third portion having a threaded hole therein for connecting within said vehicular ladder rack having a smooth hole therein for preventing sliding movement of the ladder. The ladder lock further comprising a tension adjusting screw and lock nut combination for insertion into said third portion from either side thereof through a threaded hole therein for adjusting the height of the frame structure. The ladder lock further comprising an adapter plate to be used in connection with a cross support vehicular roof rack, said adapter plate having fastening means therein for fastening to a cross support upright bracket vertically and having a channel formed therein for seating said flat stock of the frame structure.